Synology Error : Invalid File Format

My DS1515 NAS packed in so had to migrate my whole systems disks to another spare 1515 which i had however it was on DSM 7.1 whereas the old one was DSM 6.x

it said i needed to repair Serviio in order to make it work but im getting an error that says invalud File Format after it downloads.

Is there a manual way to install this or is DSM 7.x just not supported?

Thanks